Door actuating mechanism



Nov. 19, 1946.

v. E. FORREST DOOR ACTUATIiWG IECHANIS! 2 Sheets-She'et 1 Filed Aug. 12. 1943 Nov. 19, 1946. v. E. FORREST DOOR ACTUATING MECHANISM Filed Aug. '12. 194:5 2 Sheets-Sheet 2 I raven/Z01" W AZZorneys Patented Nov. 19, 1946 oFFlca DOOR ACTUATING MECHANISM Victor E. Forrest, Minneapolis, Minn. I Application August 12, 1943, Serial No. 498,308

Claims. (CI. 20-19) This invention relates to door constructions and more particularly to vertically movable doors which are especially adapted for use to close wide door openings on buildings such as aircraft hangars.

Difficulty has been encountered with large doors such as hangar doors, since their size makes it difficult to apply equalized forces thereto at numerous points for smooth and even opening and closing operations. As a result these doors are frequently made in sections with each section operable separate from the others.

It is a general object of my invention to provide a door construction particularly adaptable for use on aircraft hangars wherein the entire door can be made in one piece and it can be readily swung up to an open position adjacent the top of the door opening without binding or twisting.

Another object of the invention is to provide improved bracing means for the door which will hold it rigidly against high winds and which is so arranged that a relatively light door panel can be substituted for the. comparatively heavy and cumbersome panels which have heretofore been found necessary.

A more specific object of the invention is to provide a collapsible door bracing structure which is made up of a plurality of collapsible units connected along the door in horizontally spaced relationship together with means for simultaneously collapsing the bracing units so that there are no unequal stresses placed upon the door or the bracing structure.

These and other objects and advantages of the invention will more fully appear from the following description madein connection with the accompanying drawings, wherein like reference characters refer to the same parts throughout the views, and, in which:

Fig. 1 is a fragmentary rear elevation of a door equipped with my bracing and operating apparatus;

Fig. 2 is a fragmentary plan view or the'bracing structure at one end of the door and also . of the power actuating mechanism;

Fig. 3 is a transverse vertical section through the door showing one bracing unit and the mechanism in side elevation;

Fig. 4 is an enlarged fragmentary detail of a portion of the collapsible bracing structure; and

r Fig. 5 is a fragmentary view partially in section of a portion of the door and one of the trackways.

' In Fig. 3 there is shown a hanger floor 6, the

forward edge of which Joins an inclined entran'ce g I Power -ramp 1. Fig. -1 shows a pair of hangar side. walls 8 and-9 and front wall portions Ill and II,

A door panel l2 extends entirely across the-door opening'between the front wall portions; l0 and i I. The upper end of the door I2 is provided with a plurality of spaced brackets l3, as shown in Fig. 5. The brackets I3 carry rollers it which ride in trackways I5, said trackways extending between a. transversely disposed memberlfi adjacent the upper edge of the door and a r'earwardly disposed horizontal anchoring member H which is suspended from a plurality of rearwardly extending I beams l8.

Rearwardly of the trackway anchoring member ii is an anchoring strap it which has suspended therefrom a plurality of spaced pairs of brackets 20. Pivotally secured between each pair of brackets 29 is one end of a strut member 2| which extends forwardly and downwardly to ply. otally connect with a bracket 22 secured to the inner side of the door it? at a point vertically intermediate the ends of said door and approximately at the center thereof. Intermediat the ends of each strut 2! is a bearing 21! which rotatably supports a rod 2d, said rod extending parallel to said door and rearwardly thereof. Keyed are pivotally connected to a brace arm 21, said arms 26 and 21 providing a jointed brace unit. The arm 21 is pivotally connected to a bracket 28 which is mounted on the door I2 near the upper edge thereof. Where the brace arms 26 pivotally connect with the brace arm 21 is a stop member 29 permitting the brace unit to break only in one direction. It is, of course, understood that there is a brace unit made up of the arms 25 and 21 for each of the strut membersZl and that these units are positioned at spaced intervals across the width of thedoor It.

The shaft 2i carries a, pulley 30 around which is extended a belt or chain 3| which runs to a pulley 32 on the stub shaft 33 of the strut 2|. The shaft 33 also accommodates a. hand operated chain 34 which can be used to rotate shaft 33 and pulley 30 to partially rotate the shaft 24 and break the joint of the brace unit 26, 21.

Mounted above and lateraliy of the right-hand side of the door as viewed in Fig. 1 is a motor 35 ha ing a worm shaft 36 meshing with a worm gear 31 on a shaft 38. The shaft 38 carries a winding drum 39 and uponthis drum is wound a cable 40. The cable extends from the drum 39 about a pulley 4| which is mounted on a vertical axis, and the cable then extends across the width cables 43 which connect with the main cable 40 so that when said cable 40 is wound on the drum 39 the branch cables 43 ,will also be drawn toward the drum 39. The end of the cable 40 and the lower ends of the branch cables 43 are con-.

nected to the outer side of the door l2 as-shown at 44 in Fig. 3, this point of connection being a considerable distance down from the upper edge of said door l2 and preferably at a point near the vertical center of said door l2. 'In the event of failure of the motor 35 and the cables 40 and 43 can be drawn toward the drum by means of a hand operated endless chain 45 which extends about a sprocket 46 on the end of the motor driven shaft 38 upon which the drum 39 is also mounted.

In order to counterbalance the weight of the .door l2 and relieve the motor 35 of excessive loads I'provide a counterweight 41 which is suspended from a cable 48, said cable also being wound about the drum 39. Thus when the door is raised and lowered the counterweight 4'! moves vertically and oppositely to the door l2 to provide substantial balance therefor. M

When the door is closed the bracing structurev is in the full line position shown in Fig. 3. In this position the strut 2| in combination with the joint brace unit 26, 21 provides rigid bracing means for said door against any forces tending to push the door inwardly. Furthermore, the lower edge of the door is positioned against the edge of the floor 6 where it meets the ramp 1. Thus any strong winds directed against the door cannot injure. it or push it inwardly. When the door is to be opened the endless chain 34 is pulled to rotate shaft 33 and pulley 30 with the resulting rotation or partial rotation of the shaft 24 which is keyed to the arm 28 of the jointed brace unit 26, 21. Rotation of the shaft 33 and pulley 30 in a clockwise direction and the brace unit 26, 21 will, therefore, break with its central pivot moving upwardly. This draws the top of the door inwardly or to the right, as shown in Fig. 3. The rollers I4 move to the right in the trackways IS. The motor 35 is then operated to rotate the drum 39 and partially wind the cable 40 on said drum. This also, of course, creates a pull on the branch cables 43 and the door will be raised, the top edge of the door moving rearwardly and the bottom edge of the door swinging upwardly and outwardly until the door reaches the dotted line position shown in Fig. 3. The dooris then in an overhead position entirely out of the way and the entire door opening is free. At the same time the cables 40 and 43 exert an upward pull on the door from an intermediate portion thereof the counterweight '41 moves downwardly as its supporting cable 49 unwinds from the drum 39. Thecounterweight, therefore, substantially balances the weight of the door l2 so that the motor 35 is not subjected to any great load. Of course, When the door is lowered the counterweight similarly balances the door I! so the door will not drop too fast.

By having the jointed brace arms 26 keyed to the shaft 24 which extends across in back of thedoor all of'the joints are broken simultaneously and there is no undue twisting strain on said shaft 24 nor upon opposite ends of the door I2.

The entire structure is relatively simple, but it is so synchronized that there is uniform force applied at all points along the door but at the same time the bracing structure is such that a relatively light door panel can be used with safety.

With the construction wide hangar doors can be constructed in a single unit, thus greatly simplifying door actuation as compared to doors which tion.

are formed in a multiplicity of. units which are actuated separately, although of course, the structure can be articulatedif such an arrange- 3 ment is desired. 7 It will, of course, be understood that various changes may be made in the form, details, arrangement and proportions of the various parts without departing from the scope of my inven- What I claim is:

l. In a vertically movable door construction, a door panel, a stationarymemb'er spaced from, an upper side of said door, a strut having its ends pivotally connected to a vertically intermediate Q portion of said door and to said stationarymemher, a jointed brace connected to said door and to an intermediate portionof said strut, said jointed brace having a locked position and a broken position, and means connected to said brace for breaking the same from its locked position. i I

2. In a vertically movable door construction, a door panel, a stationary anchoring means spaced from an upper side of said door,'a plurality of struts having their ends pivotally connected to vertically intermediate portions of said door and to said stationary anchoring means, said points of connection with said door and said anchoring means being in alignment, a plurality of jointed braces connected to.said door and to intermediate 3 portions of said struts, and a common joint breaking means connected to said jointed braces and operable to break said joints simultaneously.

3'. The structure in claim 2 and said joint breaking means comprising a shaft connected to a portion of each of said jointed braces for movement therewith, wherebyrotation of said shaft will break all of said joints together.

4. In a vertically movable door construction, a door panel, a stationary member spaced from an upper side of said door, a strut having its ends pivotally connected to a vertically intermediate portion of said door and said stationary member, a collapsible brace connected to said door and to an intermediate portion of said strut, and a pair of spaced, substantially horizontally disposed trackways extending laterally relative to the upper edge of said door, and track followers secured to said door at its upper edge and movable in said trackways.

5. In a vertically movable door construction, a

door panel movable to open and closed positions,

vrc'ron E. FORREST. 

